an onmi-directional antenna's directivity is lower than 1

[kevggion]

onmi directional antenna*

Hi everyone


I have faced a problem that the directivity of simulated antenna, half-wavelength slot antenna, is lower than 1 (an omni-directional dipole antenna ususally get 1.6 approximately ). Can any of you help me to figure out the problem.

Thanks so much.

 

[shameemkabir]

onmi directional anthena

your antenna is a resonant structure at around 4 GHz I guess. therefore, you should look at the radiation pattern at that frequency not at 1 GHz.

I've simulated your structure and found that your antenna has directivity around 2.5 dB at 4 GHz.